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G. ARTHUR.

ELECTRIC WATER HEATER.

APPLICATION FILED JULY 6. I918 Patented July 8, 1919.

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' UNITED STATES PATENT, ornioa.

GUY ARTHUR, .01 mr'zvrm,

BITZVILLE, WASHINGTON, A 0

WASHINGTON, ASSIGNOB T0 ARTHUR-FOWLER 00., OF

OBPOBA'IION OF WASHINGTON.

ammo warm-Hanan. 0 specification 01' Letters na t t d July 3, 1919,

Application filed July 8, 1918. Serial ll'o. 248,848.

. type.

One of the objects of this invention is to provide an insert electric heater adapted to be disposed in a water tank and constructed to contain the water to be heated, or admit the same, cold, and then discharge the heated water at a point remote from the point of admission, thereby causing a circulation of water in the tank in efl'ecting the heating of the water.

In the most improved embodiment, my device is in the form of a tubular heating means which is proportioned to extend vertically substantially throughout the length of a water tank, the tubular means havm an intake adjacent to the lower portion 0 the tank and an outlet adjacent to the upper portion of the tank so that as the water. is

heated in the tubular means, it rises to the top of the tank and discharges thereinto.

--Water tanks for household use are provided with water outlet and the device of my invention is especially designed for this type of tank. However, it is a feature of my invention to hot water may be drawn off directly from the tubular means, as well as through the usual hot water outlet pi e In t he most improved embodiment, my invention comprises an inner heating tube surrounded by an outer protecting tube with a suitable intervening an space between the tube and pipe. At one end, the tube and pipe are connected in a manner to render it impossible for water to enter'between the and at the remainingend, a suitable packing device is provided whereby one tubular member may move with respect to the other, to take up for difference in expansion, the packing device likewise being, a water-tight connection. Interposed between the pipe and tube, is a heating coil having a novel mounting on the tube whereby the heat of the coil is practicall concentrated on thetube and is prevented rom radiating a cold water inlet and a hot.

households and illustrating the application 7 I of the device of my invention thereto.

Fig. 2 is an enlarged contracted sectional view of the device of my invention.

Fig. 3 is a detail sectional view on line 33 of Fig. 2.

Like characters of reference designate similar parts throughout the different figures of the drawin As illustrated, 1 esignates a typical form of water heating tank, for which my invention is designed, the tank having a bottom 2 and a top 3. Thegtop 3, of a tank of this type, is usually provided with a threaded bore 4, for insertion of the usual cold water feed pipe which extends downwardly in the tank to a point near the bottom 2. These tanks are also provided with anadditional threaded bore 5, in the bottom 2, for a cold water inlet, and with a threaded bore 6 in the top for a hot water outlet. In installing my improved device, which is generally indicated at 7, 'I remove the cold water pipe and substitute the device of my invention, connecting the tank 1 for cold water supply by a pipe 8; The hot water drawoif is indicated at 9 and this need not be altered. The foregoing relates specifically to the application of my invention to this particular type of tank but it will be understood that my invention is not limited to this particular utility.

As shown, my invention includes an inner heating tubelO' which is formed of very thin material of a character to efficiently conduct. heat. Surrounding the heating tube 10, and preferably in concentric relation with respect thereto, is a protecting pipe 11. The size of the tube and pipe, as regards the diameter thereof, 1s such that an intervening air-space 12 is formed therebetween.

A heatingcoil 13 is wound about the tube 10, in the intervening space 12. In the speto use mica, as indicated at 14. It 'is cific form shown, the tube 11 is dperipherally covered with a very thin an preferably hard electrically insulating material whic is also a good conductor of heat. I lpirefer s about this soft insulating material to embed therein. I have found that hot water flax packing, as indicated at 15, sufiiciently per.- forms this function because it is also a good conductor of heat as well as bein an electric insulator. Thus it will be seen rom Fig. 3, that the bare wire forming the coil can be wound sufiiciently tightly on the soft flax packing to embed therein in a manner to ispose the wire very close to the mica. In

fact, the bare wire is shown flush with the periphery of the soft packing, which is possible although not absolutely necessary. Finally, I cover the bare wire with soft insulating tape 16, or any other insulating material which is a poor conductor of heat. With this construction, in addition to the air space 12, it will be seen that ractically all of the heat from the coil 13 wi 1 be localized on the heating tube 10. Furthermore, the tape 16 will function in addition to the soft packing 15, to prevent the convolutions of the coil from getting'out of position.

In cases where the device of my invention is used in connection with a closed water tank, as illustrated, I provide a novel form of water-tight connection between the pipe and tube, 11 and 10, respectively, embodied in a fitting structure adapted to have threaded connection with the wall portion of the tank.

its illustrated, a fitting 17 of tubular form is e-Xteriorly threaded, as indicatedat 18, and is adapted to be turned into position in the threaded bore 1, of the head 3, to dispose the heater inside the tank. The lower portion of the fitting 17 is reduced to rovide an annular seat for the u per en of pi e 11, as indieeted'at 19. he pipe 11 wi be suitably secured in water-tight engagement to said annular seat 19. The upper end of heating tube 10 projects into the fitting -17 and a suitable head 20, may be bored, as shown, to form a water-tight cpnnection between the tube 10 and the fitting 17 and to securely hold the tube 10 to the fitting 17. A hot water discharge outiet 21 forms constant communication between the upper end of tube 10 and the upper ortion of the tank .1. An 0 ing' 22, m t e 11 per portion of the hes permits of with rawal of hot water directly from abreast 0 the tube 10 upwardly through the fitting 17. The upper end of the fitting 17, exteriorly of the tank, is provided with a suitable angle union 23 from which a pipe 24 leads.

Flow through the pipe 24 may be controlled by a suitable cock not shown. It will be understood that my improved device is' protecting pipe 11 will alwa s be at a lower temperature than tube 10, therefore provide means for taking .care of unequal ex-' ansion, such means preferably being at the ower end of the pipe and tube.

As illustrated, the lower terminal of the tube'lO is slightly above the terminal of the end pipe 11. An upper packing nut or abut- -ment 25 may be threaded into the interior of pipe 11. Such nut 25 is provided with asmooth bore for contact with the periphery of tube 10. Packing 26 will be compressed between the tube 10 and pipe 11 by means of a. lower packing nut 27 This lower packing nut 27 likewise. has threaded connection with the interior of pipe 11 and a smooth bore fitting about the periphery of tube 10 so that the tube may contract or expand freely as regards the nuts 25 and 27 and the packing at all times will maintain a water-tight connection to prevent water from entering the intervening space 12.

If the rate of the flow of the water upwardly through the heating tube 10, as a result. of the heating action of the latter, is relatively rapid, then the Water will not be heated to as high a temperature as though the flow was restricted. Therefore I provide means for restricting the rate of flow upwardly through the tube 10.

,. In the specific form shown, a rubber washer 28 of a diameter substantially equal to the internal diameter of pipe 11, is disposed in position shown with the washer the terminal end of the tube 10. The lower packing nut 27 serves as an upper abutment for the washer and a washerhclding nut 30, having an enlarged bore 31, is threaded into the pipe 11 to clamp the washer 28 into position shown.

If desired, the washer 28 may be clamped -into engagement with terminal end 29.

However, the main function of the washer 28 isto provide a restricted flow by means of the relatively small a rture 32. The rate of flow can be fix by substituting washers having apertures of difierent sizes.

. For instance, if it was desired to heat the water to a very high temperature, a washer I ClfiC manner in which these will be delivered while I have herein shown an one specific form of of the very small aperture would be provided, and for a relatively lower temperature, a washer with a'relatively larger sized aperture would be provided. I, preferably use a rubber washer because lime does not encrustate on rubber and therefore the a erture would always remain open, and 0 its initial size.

The" terminals 33 and 34, of the heating coil, are diagramatically shown as passing upwardly through the fitting 17, the speterminals are protected not being a feature of this particular application.

It will seen that the protecting pipe 1 1 protects not only the tube 10 but the heating coil 13 from direct cooling influence of the body of water in the tank 1, and therefore, practically the entire heat from the coil 13 may be localized upon tube 10 without any cooling action whatsoever.

By1 making the devlce of my invention in t e form of an insert, I can provide a very small heating tube 10, in view of the fact that the latter extends practically 'coextensive with the length of the tank, and at the same time, I present to the water in the tube 10 a relatively extensive heating area. Thus while the water. in the main body of the tank the top of the tank and by reason of the circulation in the tank, the contents of the latter will be verfyl quickly heated.

It is believed t at the utility and advant-ages ofmy invention will be clearly understood by the foregoing descri tion, and described my invention, I do not wish to be limited thereto except for such limitations as the claims may import.

I claim- 1. An electricwater heater for closed water heating tanks, com rising in combination, a water heating tu havi an intake opening near the bottom of sai tank and an outlet discharging near the top of said tank, a protecting ipe of enlarged diameter with respect to said tube and sald pipe having watertight connection with said tube to form an intervening air-chamber, the exterior of said tube inside of said p' being covered with a heat conducting andblectrical insulating material of a thin hard nature, a soft insulatin material covering said hard material, a heating coil of bare wire ti htly wound about the soft insulating material to embed therein, and a non-heat conducting and electrical insulating materialcovering said bare wire and in spaced relation from said protecting pi to .afiord an air space whereby radially inwardly against said heating tube, substantially, as described.

(and

may be cold, hot water through opening 21 into.

' protecting the heat t erefrom will be directed ment In combination, having a cold water inletpipe opening into the bottom of said of sai tank, a water heating tube device fixed in said tank and having a cold water inlet disposed at the lower portion of said tank and a hot water outlet near the top of said tank whereby the water admitted to the lower end of said tube will be heated and rise and be discharged into the upper end of said tank, and being constructed for drawing off hot water exteriorly of the tank and directly from said tube device, substantially. as described.

3. In combination, a water tank, and an electric water heater comprising an inner heating tube and an outer protecting pipe, a fitting adapted to be fixed in the Wall of said tank and having water-tight connection with said pipe to support the heater, a head fixed in said fitting and havin watertight connection with the end of said tube,

and a discharge outlet opening to the tank I extending from the inner tube outwardly thro h said head and fitting, substantially as gescribed.

4'. In combination, a water tank, an electric heater therefor comprising a tubular fitting adapted to be fixed to the wall of the tank and having a hot water draw oif exteriorly of the tank, a protecting pipe having water-tight connection with the interior and of said fitting, a head having watertight connection in the interior of said fitting, a water heating tube in saidpi e havmg weter-tight connection with said head, said head having an opening for discharge of hot water from said tube directly through said fitting and out of said tank, and an opening establishin communication between the said tube and 51B interior of said tank, substantially as described.

5. In an electric water heater, an inner heating tube having an intake end, an outer pipe surrounding said tube In spaced re tion therewith and projecting beyond the intake end of said tube, a washer in said intake end having a restricted opening and said washer being of a diameter substantially equal to the interior diameter of said pipe, a packing nut in threaded engagement with and in smooth engagement with the exterior of vsaid tube and forming an upper abutment for said washer and a lower packing abutment, a washer nut engaging the opp0- site face of said washer latter against said lower the terminal edge threaded and holding the packing nut and of said tube and havin engagement with the interior 0% said pipe, a packing filling the space between said pipe and tube above said lower packing nut for a slight distance, and an abutabove said packing nut whereby the a water heating tank tank and a .hot water outlet (pipe leading from the upper portion the threaded interior of said plpe form a water-tight connection between said a pipe and tube, substantiall as described.

'6'. In an electric water eater, an inner heating tube having an intake end and a discharge end, a coil for heating said tube, a pipe surrounding ing a rigid the tube to prevent water from entering between the tube and pi e, and acking means slidably connecting e inta e end of the tube with said pipe to allow for unequal expansion and to prevent water from entering between said tube and pipe, substantially as described.

7. In an electric heater, an inner tube,

said tube, means form-- and water-tight connection with said pipe and tube at the discharge end of 7 having a water intake and a discharge end, a coil for heating said tube, and flow controlling means, interchangeable in said tube, for limiting the rate of flow of the water through said tube to determine the temperature of heat supplied to the water by said tube, substantia ly as described.

8. In an electric water heater, an inner tube, a pipe surrounding said tube, a heating element therebetween, and packin means slidably connecting adjacent ends 0 said pipe and tube to allow for unequal expension and prevent water from entering so between said pipe and tube.

In testimony that I claim the foregoing as my own, I'hereby afiix m si nature.

GU A THUR. 

